Hey t-marinho,
Importing data from an Excel file is a quick and convenient way to bring in the most important information. QuickBooks Online makes it easy to import lists, invoices, and bills so you'll always be all set to run your business. Currently, the easiest way to bring in a journal entry it to create it from the + New button. For a full list of what can be imported, check out this great guide: Common questions about importing data to QuickBooks Online
I'm here for you. Feel free to reach out if you have any other questions!